Commit eefef1cf authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
Browse files

net: add ARP notify option for devices 



This adds another inet device option to enable gratuitous ARP
when device is brought up or address change. This is handy for
clusters or virtualization.

Signed-off-by: default avatarStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ead73183

Documentation/networking/ip-sysctl.txt

+6 −0
Original line number Diff line number Diff line
@@ -782,6 +782,12 @@ arp_ignore - INTEGER 
	The max value from conf/{all,interface}/arp_ignore is used

	when ARP request is received on the {interface}



arp_notify - BOOLEAN

	Define mode for notification of address and device changes.

	0 - (default): do nothing

	1 - Generate gratuitous arp replies when device is brought up

	    or hardware address changes.



arp_accept - BOOLEAN

	Define behavior when gratuitous arp replies are received:

	0 - drop gratuitous arp frames

include/linux/inetdevice.h

+1 −0
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev) 
#define IN_DEV_ARPFILTER(in_dev)	IN_DEV_ORCONF((in_dev), ARPFILTER)

#define IN_DEV_ARP_ANNOUNCE(in_dev)	IN_DEV_MAXCONF((in_dev), ARP_ANNOUNCE)

#define IN_DEV_ARP_IGNORE(in_dev)	IN_DEV_MAXCONF((in_dev), ARP_IGNORE)

#define IN_DEV_ARP_NOTIFY(in_dev)	IN_DEV_MAXCONF((in_dev), ARP_NOTIFY)



struct in_ifaddr

{

include/linux/sysctl.h

+1 −0
Original line number Diff line number Diff line
@@ -490,6 +490,7 @@ enum 
	NET_IPV4_CONF_ARP_IGNORE=19,

	NET_IPV4_CONF_PROMOTE_SECONDARIES=20,

	NET_IPV4_CONF_ARP_ACCEPT=21,

	NET_IPV4_CONF_ARP_NOTIFY=22,

	__NET_IPV4_CONF_MAX

};

kernel/sysctl_check.c

+1 −0
Original line number Diff line number Diff line
@@ -219,6 +219,7 @@ static const struct trans_ctl_table trans_net_ipv4_conf_vars_table[] = { 
	{ NET_IPV4_CONF_ARP_IGNORE,		"arp_ignore" },

	{ NET_IPV4_CONF_PROMOTE_SECONDARIES,	"promote_secondaries" },

	{ NET_IPV4_CONF_ARP_ACCEPT,		"arp_accept" },

	{ NET_IPV4_CONF_ARP_NOTIFY,		"arp_notify" },

	{}

};

net/ipv4/devinet.c

+9 −0
Original line number Diff line number Diff line
@@ -1075,6 +1075,14 @@ static int inetdev_event(struct notifier_block *this, unsigned long event, 
			}

		}

		ip_mc_up(in_dev);

		/* fall through */

	case NETDEV_CHANGEADDR:

		if (IN_DEV_ARP_NOTIFY(in_dev))

			arp_send(ARPOP_REQUEST, ETH_P_ARP,

				 in_dev->ifa_list->ifa_address,

				 dev,

				 in_dev->ifa_list->ifa_address,

				 NULL, dev->dev_addr, NULL);

		break;

	case NETDEV_DOWN:

		ip_mc_down(in_dev);
@@ -1439,6 +1447,7 @@ static struct devinet_sysctl_table { 
		DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"),

		DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),

		DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"),

		DEVINET_SYSCTL_RW_ENTRY(ARP_NOTIFY, "arp_notify"),



		DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"),

		DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"),